Syntheses of regular copolyamides using triphenyl phosphite and pyridine

In this article, a method of preparing of regular copolyamide (co-PA) in a reactor using triphenyl phosphite/pyridine as the activating agent was inve stigated. In two-step reactions of copolymers prepared from two kinds of di carboxylic acids and one kind of diamine, oligomer PAs containing amine end groups were first synthesized; then, the second dicarboxylic acid was adde d to the same reactor to polymerize high molecular weight and regular co-PA s. However, when oligomers having carboxylic acid end groups were first pre pared and another kind of diamine was added, the degree of polymerization w as low. The reason proposed was that if the oligomer has an amine end group , it would coexist with the activating agent without deactivating; if the e nd group was the carboxylic acid end group, deactivation would occur. (C) 2 000 John Wiley & Sons, Inc.